DAKAR, Feb 15 (Thomson Reuters Foundation) - Survivors of last year's devastating mudslide in Sierra Leone are struggling to keep their children in school as aid efforts wind down and many are left jobless, several charities said.

More than 500 people were killed and 3,000 left homeless when a mountainside collapsed in mid-August outside the capital Freetown - one of Africa's deadliest mudslides in decades.

Almost half of the affected families now have no source of income, compared with just 5 percent before the mudslide, found a survey published this week by British charity Street Child.

About four in 10 families said their children had dropped out of school or were at risk of doing so because they could not afford the fees, the survey of more than 300 households showed.

"If the landslide ends up curtailing the education of children in Freetown, the negative impact will be felt throughout those children's lives," said Hamid El-Bashir, country representative for the U.N. children's agency UNICEF.

Many families have used handouts from aid agencies to cover school costs since the mudslide, El-Bashir said, leaving many children at risk of losing their education if funding dries up.

The government closed its emergency camps in November and most relief programmes ended at that time, aid agencies said.

"When the funds dried up, work stopped, and there was still a lot to be done," said Eric Hubbard of Catholic Relief Services, which is working to improve drainage systems in the flood-prone area to avoid a repeat when the next rains arrive.

Although the government has urged people to move away from the high-risk zone, some have resisted because they did not have job opportunities or connections elsewhere, Hubbard said.

The Sierra Leone Red Cross has extended its cash transfer programme for survivors until June and hopes to address their most urgent needs by then, said spokesman Abu Bakarr Tarawallie.